gms | German Medical Science

Objectives/Interrogation: Carpal tunnel release (CTR) is often performed under local anaesthetic (LA), as a day case. Streamlining the operation to better utilise healthcare resources, and improve the patient experience, led us to compare the use of wide awake local anaesthesia no tourniquet (WALANT) with 'standard' LA and tourniquet (LAT).

Methods: We retrospectively identified and analysed the data of patients who underwent CTR; consulting electronic records, operation notes, self-reported Visual Analogue Scale (VAS) pain scores, and satisfaction reports. WALANT technique involved subcutaneous infiltration of 4.4 ml 2% lignocaine with 1:80,000 adrenaline; 15-20 minutes pre-operatively. LAT technique employed plain Lignocaine and Levobupivicaine (injected in the same manner) with the addition of an upper arm tourniquet for the operative dissection.

Results and Conclusions: 46 patients underwent CTR; 22 had WALANT, 24 had LAT. Mean VAS pain scores (0-10 point Likert scale; 10 being most painful) were 0.73 and 1.88 respectively. With the exception of 1 outlier the WALANT cohort all reported pain scores of 3 or less; whereas 5 LAT were recorded at 5 or over. That this descriptive trend was not found to be significant (Mann-Whitney U test p<0.05) inferentially, is likely to represent a type 2 error, as extending to a p=0.08 results in significance. Reasons for discomfort in the WALANT group were deep nerve pain (n=4) and retractor discomfort (n=1). Patients in the other group noted deep nerve pain (n=6) and tourniquet pain (n=5). 93% were extremely satisfied and all would recommend this technique.

Our infiltration volume is smaller than original WALANT descriptions and this may account for intraoperative pain in some patients. In larger hands we recommend increasing volumes, and waiting longer than 20 minutes.

In summary, both methods were acceptable in terms of pain, efficacy and satisfaction. This supports the literature that WALANT is at least as good as the standard LA/tourniquet method for most cases, and would transfer readily to an outpatient procedure room setting if this became a necessity.